Oxidant. Catalysts for organic reactions. The analysis of iron and steel is used as the standard sample of rare earth metals. Redox titration analysis. Decoloured glass. Glass enamel shading agent. Heat-resisting alloy. It can be used as additive in glass industry, grinding material for plate glass and anti-ultraviolet in cosmetics. At present, it has been extended to the grinding of glasses, optical lenses and picture tubes, playing the roles of decolorization, clarification, absorption of ultraviolet rays and electronic wires.